Enantiopure (99% ee) cis- and trans-gamma-benzylparaconic acids and their ethyl esters were synthesized by a procedure involving kinetic enzymatic resolution of the corresponding lactonic esters with alfa-chymotrypsin (a-CT) with acetone added as a cosolvent. Their absolute configurations were determined by 1H NMR analysis of their 1-(9-anthryl)-2,2,2-trifluoroethyl esters.
